1. Field of the Invention
The present invention relates to method and apparatus for peeling a releasable sheet from an adhesive layer of a tape (or label tape) which is comprised of a tape base having the adhesive layer and the releasable sheet removably adhered to the adhesive layer.
2. Description of Related Art
A tape printing device for making a printed adhesive tape (also known as a label tape) having a releasable sheet removably adhered to the adhesive layer of the label tape is well-known. The label tape includes an image receiving tape upon which characters are printed, an adhesive layer on a back side of the image receiving tape, and a releasable sheet removably adhered to the adhesive layer. The image receiving tape and adhesive layer together define a tape base. The tape printing device outputs the label tape including the releasable sheet by printing desired characters and symbols on the tape base of the label tape using, for example, an impact printing head, an embossing printing head, or a thermal printing head. The tape printing device also cuts the label tape into a predetermined length. In order to adhere a label made by the tape printing device to a label receiving member, the releasable sheet is removed from the adhesive layer by peeling so as to directly expose the adhesive layer, which is then adhered to the label receiving member. For an example of a tape printing device which uses a thermal printing head to form the above-described label tapes, see U.S. Pat. No. 4,927,278 to Kuzuya et al, the disclosure of which is incorporated herein by reference.
When an operator peels the releasable sheet from the tape base of the label, the operator folds down one end of the label in order to form a space between the adhesive layer and the releasable sheet. The operator then inserts an object such as a claw into the space in order to peel the releasable sheet from the adhesive layer.
When the releasable sheet is removed by the above-described method, the tape base is folded. Folding the tape base causes problems in that it is difficult to adhere the folded portion of the label to the label receiving member, or the label is easily removed from the label receiving member (since the folded portion may not adhere well to the label receiving member).
U.S. Pat. No. 3,310,145 discloses a hand-operated tape embossing tool having a tape cutting device comprising a cutting blade for cutting entirely through the tape, and a slitting blade for cutting only the tape base including the adhesive layer (i.e., a releasable backing layer is not cut by the slitting blade). Thus, the tape cutting device is a compound cutting device which can cut entirely through the tape and form a half cut portion on the tape at the same time.
When the operator peels the releasable backing layer from the tape base, the operator folds the tape at the half cut portion. Then, the tape base including the adhesive layer is peeled from the releasable backing layer at the half cut portion.
However, with the above-described type of tape cutting device, a space must be provided between the slitting blade and an anvil which confronts the slitting blade. The space is provided so that the slitting blade only cuts through the tape base including the adhesive layer without cutting through the releasable backing sheet. Therefore, a special construction for adjusting the space is required, and the point where the slitting blade confronts the anvil must be determined exactly. Accordingly, the construction for supporting the slitting blade is complicated, and the cutting device is costly to produce. Additionally, installation of the slitting blade in the tape cutting device can be complicated.